Method of and apparatus for conditioning air



@cfl; 19360 T. E. FOULKE 9 9 METHOD OF AND APPARATUS FOR CONDITIONING AIR Original Fild Feb. 7, .1935

AIR, MET BLOWER v OZOMIZER SLE BLOWER, ozomza 3 w w k T INVENTOR @aiented ct. 1936 eerie WTHQD @F AND APPARATUS FQR @QNDITIONING AIR lied 1E. Foullre, Nutley, N. .l., assignor to General Electric Vapor Lamp Company, Hobolren, N. if... a corporation oi New Jersey Original application February 7, 1933, Serial No.

liliivided and this application March.

313, 1935, Serial No. M386 3 @laims.

The present invention relates to the art of conditioning air with ozone, and more particularvide a novel method of controlling the ozone concentration in conditioned air. Another object of my invention is to provide a novel means to control the amount or ozonization of the air. Still another object of my invention is to provide a novel method of operating an ozone generating apparatus. Still other objects and advantages of my invention will appear from the following detailed specification or from an inspection of the accompanying drawing.

It is well known that the conversion of oxygen to ozone can be readily produced by means of a corona or silent electric discharge, and various devices have been utilized to produce this result, a particularly desirable apparatus being shown in my co-pending application, Serial No. 655.653, filed February 7, 1933, of which this case is a division. These devices are frequently used to freshen and purify the air in a room, either alone or in combination with humidifying and other conditioning means.

in some cases, as {where such an ozonizer is used in relatively small rooms, the ozone produced occasionally becomes too concentrated for com-tort, especially under certain atmospheric conditions. In such a case some means of controlling the amount of ozone produced is obvi= ously necessary. I have now discovered a novel apparatus and a novel method of operation, whereby the ozone concentration is continuously maintained at any desired value under any cir-- cumstances. According to this novel method the air in the room is continuously tested, and the operation of the ozonizer is determined by or based upon the results of this test.

For the purpose of illustrating my invention I have shown several embodiments thereof in the accompanying drawing, in which Fig'. 1 is schematic diagram showing my novel arrangement of apparatus for maintaining predetermined ozone concentration in the air oi a .room or building, and

Fig. 2 is a schematic diagram showing a modification oi the apparatus of Fig. 1.

Wherever ozonizers have been used. to condition air it has been found that the concentration of ozone may become unpleasant after long continued operation, and that this condition may exist even though the voltage of the silent discharge is decreased as much as possible, for the ozone production varies but little with changes 5 in the applied voltage, within the range of vari= atiou which is possible. The apparatus schematically shown in Fig. 1 overcomes this dimculty by automatically shutting down the ozonizer whenever the ozone concentration reaches a pre- 10 determined value. The air conditioning apparatus schematically illustrated has a blower or fan ill which takes air from the room or other enclosed space whose air is to be conditioned and passes it through a pipe ii to the ozonizer i2,

after which it is again returned to the room. Said ozonizer l2 preferably comprises apparatus of the silent discharge type, such as disclosed in my co-pending application to which reference has been made hereinbefore. tainer it contains a reel of paper ribbon it, while a reel l5 which is continuously or intermittently driven by any suitable driving mechanism has one end of said ribbon is attached thereto, and slowly pulls saidribbon out of said container 53. A small tube 66 leads from the pipe i i to a point adjacent to the ribbon it near where the latter emerges from said container 83, and continuously directs a stream of air on said ribbon i l. Said ribbon is coated with any subso stance or substances which will indicate by a change or color or shade the presence of ozone in this air. For example, I prefer to use a coatingcomprising a mixture of potassium iodide and starch, this mixture turning from white to blue in the pressence of ozone. A suitable light source ii directs a beam of light onto this ribbon i l at or Just below the point at which the air stream impinges thereon. A photo-electric cell it which is m so placed as to receive the light reflected from said ribbon is connected through an amplifier it to the magnet coil of a relay 20. The contacts of said relay are connected in the energizing circuit of the ozonizer l2, said contacts being biased to the open circuit position.

In the use and operation of the apparatus shown in Fig. 1 a sample of the incoming air, which is typical of the air in the room, is directed in a. continuous stream upon the coated ribbon I4. If there is no ozone in this air the coating will be unchanged and the light reflected from said ribbon to the photo-electric cell IB will be a maximum. Sufficient current will there- A suitable cong9 upon flow through the coil of the relay 20 to keep the contacts thereof closed, with the result that the ozonizer I2 is continuously operated to increase the ozone concentration of the air in the room. As the ozone concentration in the room is thus increased the ozone content of the air which is borne against the ribbon ll increases in like proportion. This ozone causes the starch-iodide coating on said ribbon to turn blue, the depth of the color depending upon the ozone concentration. As the color of the coating thus changes the light which is reflected therefrom to the photoelectric cell I8 is reduced, causing a reduction in the current which flows through the coil of the relay 20, until at some predetermined value the contacts of said relay are allowed to open, thus shutting down the ozonizer 12. Due to the movement of the ribbon ll a fresh portion thereof is then brought into the path of the air from the tube l6 and likewise into the field of the photoelectric cell i8. Hence as the ozone concentration decreases the coating on the fresh portions of said ribbon will be gradually turned less blue, and more and more light is thus received by the photoelectric cell l8. When the ozone content has decreased to a predetermined value the contacts of the relay 20 will again be closed, restarting the operation of the ozonizer l2. Said ozonizer is thus intermittently operated for periods sufflcient to maintain the ozone concentration substantially constant at a desired value. This concentration may be varied at will, however, by varying the'gain in the amplifier l9, or by varying the resistance in the circult of the photoelectric cell 3, as well as in various other ways. Where the photoelectric cell I 8 has a relatively low response to blue light as compared to light of longer wave lengths the sensitivity of the apparatus may be greatly increased. Several cells having such a characteristic are now available on the market. Where the response of these cells is sufiicient the amplifier may, of course, be omitted. It is to be noted that with the arrangement of apparatus shown in this figure any failure of a unit such as the photoelectric cell, the light source, the ribbon driving mechanism, or the amplifier will automatically shut down the ozonizer, so that the ozone concentration can never become too great, despite any such mishap. l t

The apparatus shown in Fig. 2 is much the same as that shown in Fig. 1 ever, a by-pass 2| is connected around the ozonizer l2, and a damper 22 is placed in the pipe ll between said by-pass and said ozonizer. Said by-pass is preferably so designed as to offer an appreciable resistance to the flow of air therethrough, including means to increase the back pressure therein whenever there is any appreciable air flow through said ozonizer 12, in order to normally force a large proportion of the air through said ozonizer without the use of an additional damper in said by-pass. Said damper 22 is biased to the closed position, but is adapted to be opened by the magnetic solenoid 23 which is actuated by the output of the photoelectric cell l8, amplified if necessary.

In this case, howwith this novel arangement, assuming that there is no ozone in the incoming air, the coating of the ribbon I4 will be unchanged, and a maximum of light will be received by the photoelectric cell l8. The current from said cell will thereupon energize the solenoid 23 and fully open the damper 22, with the result that the maximum proportion of air will be passed through the ozonizer 12. The ozone concentration of the air in the room is thereby rapidly increased. This increase in ozone concentration is reflected in an increasing change in the color of the coating on the ribbon M, with a corresponding decrease in the amount of light reflected to the*photoelectric cell l8. The current from said cell thereupon gradually decreases, with the result that the damper 22 is gradually allowed to close, diverting more and more air from the ozonizer I2. Since the ozone output from said ozonizer is substantially proportional to the volume of air passing therethrough (assuming that it is operating at high efficiency at maximum flow) a constantly decreasing amount of ozone is added to the air. At a predetermined ozone concentration a state of equilibrium is attained, exactly enough ozone being added at all times to just maintain the desired concentration. As in the apparatus of the previous figure, any failure ofa unit in the ozone measuring unit results in the automatic closing of the damper 22, so that an excess of ozone will never be produced.

While I have described my invention by reference to a specific embodiment, it is to be understood that my invention is not limited thereto, but that various changes, substitutions, or omissions, within the scope of the appended claims, may be made in the method and in the apparatus shown and described without departing from the spirit of my invention.

I claim as my invention:

1. In an air conditioning apparatus, in combination, an ozonizer, a movable element whose position controls the rate of production of ozone by said ozonizer, means to determine the ozone concentration in the air and to vary the position of said movable element in accordance with said concentration whereby said ozone concentration is maintained at a predetermined value.

2. In an air conditioning apparatus, in combination, an ozonizer, an air duct leading thereto, a by-pass about said ozonizer, a damper whose position controls the proportion of the air from said duct which traverses said ozonizer, means to determine the ozone concentration in the air and to vary the position of said damper in accordance therewith.

3. In an air conditioning apparatus, in combination, an ozonizer, an air duct leading thereto, a by-pass about said ozonizer, means comprising a damper to vary the proportion of the air from said duct which flows through said ozonizer, means including a photoelectric cell to vary a current in accordance with the ozone concentration in said duct, and means responsive ,to said current to move said damper to decrease the proportion of the air flowing through said ozonizer as said ozone concentration increases.

- TED E. FOULKE. 

